I'll start off by saying I use Linux (Ubuntu 20.04). Not sure if this will make a possible solution harder for some to suggest as i don't know how different the setup will be in windows.
Due to the limited space i have, I only have a small monitor with one HDMI input and to keep things neat, I use a 5 way HDMI switch so i can just have a single HDMI cable and the IEC lead to my monitor.
For my audio, I use USB and as that is digital audio, I struggle to understand how anything related to HDMI can interfere with that, but it does on some applications.
I use Pulseaudio to control my audio on Ubuntu and have HDMI audio set at off. But I'm guessing when i switch HDMI inputs on my HDMI switch (equivalent to unplugging and then reinserting the HDMI cable on the PC), it seems to briefly cut out the USB audio, then receives it again. But on applications like steam and when gaming and i want to change input to set something to record on my tv box for example, after i switch back to my pc, there is a load of popping and crackling that seems to have been a result of changing inputs and going back. This popping and crackling goes on for quite some time and often the system needs a reboot before it is solved. It will then be fine again until i switch input.
It only occurs while audio is being played and is just a random load of quiet/loud pops on the left or right channel. Restarting the application won't help.
I believe this has always been a problem, but has just been more noticeable recently.
I have tried a lot of things that can at least confirm several things that are not the cause which i will list below.
I've tried with 3 USB audio DACS (SMSL M3, FiiO X3 and FiiO E10) and all all have the same issue. Have also tried different USB ports. I want it to be in the USB 2.0 card i added, but I tried the normal motherboard ports as well as one from the front of the case and all are the same.
I've tried 3 different HDMI cables, both through the switch and directly to my monitor. If connected directly, unplugging it and reinserting it is what introduces this interference to the USB audio.
I've also used another HDMI switch which does the same thing when changing inputs then going back to the PC output and again, doesn't solve the issue.
I then thought I could try using a DVI - HDMI cable from my graphics card to my HDMI switch as until now, I thought no sort of DVI was even capable of carrying audio, but i then found out that the graphics card effectively sends it the HDMI signal as that is what it gets converted to at the other end and it has enough pins to also carry the audio, so this didn't solve the problem either. Same whether connected to my monitor or HDMI switch.
A DVI to DVI cable directly to my monitor obviously can't carry audio, and even when attempting to have the HDMI and VGA inputs used on my monitor and switching between inputs, the computer USB audio this time does not get messed up.
So, my thoughts are that if there was such a thing as an HDMI cable that was not capable of carrying audio, this issue likely would be gone entirely, but that isn't something I will be able to get hold of.
Something else interesting but confusing worth mentioning is that the if i select the computer audio to output through onboard audio 3.5mm ports, switching inputs on my HDMI switch doesn't interfere at all. It is almost as if the digital audio of HDMI interferes with USB as it is also digital. But I thought digital audio was supposed to be clean!
At the moment, I'm just putting up with using DVI - DVI for my PC to avoid this messed up sound occurring, but as a result, i can't use my HDMI switch remote to change inputs which is really handy. My other option is to use the onboard sound from the motherboard, but that just isn't as good as using my DACs.
Is there any way on Ubuntu of fully disabling HDMI audio so it isn't possible for the PC to even attempt to briefly switch back when the cable is inserted? I feel that is the cause of it.
Due to the limited space i have, I only have a small monitor with one HDMI input and to keep things neat, I use a 5 way HDMI switch so i can just have a single HDMI cable and the IEC lead to my monitor.
For my audio, I use USB and as that is digital audio, I struggle to understand how anything related to HDMI can interfere with that, but it does on some applications.
I use Pulseaudio to control my audio on Ubuntu and have HDMI audio set at off. But I'm guessing when i switch HDMI inputs on my HDMI switch (equivalent to unplugging and then reinserting the HDMI cable on the PC), it seems to briefly cut out the USB audio, then receives it again. But on applications like steam and when gaming and i want to change input to set something to record on my tv box for example, after i switch back to my pc, there is a load of popping and crackling that seems to have been a result of changing inputs and going back. This popping and crackling goes on for quite some time and often the system needs a reboot before it is solved. It will then be fine again until i switch input.
It only occurs while audio is being played and is just a random load of quiet/loud pops on the left or right channel. Restarting the application won't help.
I believe this has always been a problem, but has just been more noticeable recently.
I have tried a lot of things that can at least confirm several things that are not the cause which i will list below.
I've tried with 3 USB audio DACS (SMSL M3, FiiO X3 and FiiO E10) and all all have the same issue. Have also tried different USB ports. I want it to be in the USB 2.0 card i added, but I tried the normal motherboard ports as well as one from the front of the case and all are the same.
I've tried 3 different HDMI cables, both through the switch and directly to my monitor. If connected directly, unplugging it and reinserting it is what introduces this interference to the USB audio.
I've also used another HDMI switch which does the same thing when changing inputs then going back to the PC output and again, doesn't solve the issue.
I then thought I could try using a DVI - HDMI cable from my graphics card to my HDMI switch as until now, I thought no sort of DVI was even capable of carrying audio, but i then found out that the graphics card effectively sends it the HDMI signal as that is what it gets converted to at the other end and it has enough pins to also carry the audio, so this didn't solve the problem either. Same whether connected to my monitor or HDMI switch.
A DVI to DVI cable directly to my monitor obviously can't carry audio, and even when attempting to have the HDMI and VGA inputs used on my monitor and switching between inputs, the computer USB audio this time does not get messed up.
So, my thoughts are that if there was such a thing as an HDMI cable that was not capable of carrying audio, this issue likely would be gone entirely, but that isn't something I will be able to get hold of.
Something else interesting but confusing worth mentioning is that the if i select the computer audio to output through onboard audio 3.5mm ports, switching inputs on my HDMI switch doesn't interfere at all. It is almost as if the digital audio of HDMI interferes with USB as it is also digital. But I thought digital audio was supposed to be clean!
At the moment, I'm just putting up with using DVI - DVI for my PC to avoid this messed up sound occurring, but as a result, i can't use my HDMI switch remote to change inputs which is really handy. My other option is to use the onboard sound from the motherboard, but that just isn't as good as using my DACs.
Is there any way on Ubuntu of fully disabling HDMI audio so it isn't possible for the PC to even attempt to briefly switch back when the cable is inserted? I feel that is the cause of it.
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